Sonochemistry in organic synthesis: A convenient method for the preparation of halo-bicyclic molecules with keten addition reaction and biological properties of Dimethyl 7,7-dichloro-8-oxabicyclo[4.2.0]oct-3-ene-3,4- dicarboxylate

Abstract

Abstract A convenient method for the preparation of halo-bicyclic molecules likely to show biological activity, from keten addition reaction with dimethyl cyclohexa-1,4-diene-1,2-dicarboxylate (3) and dichloroketene, respectively, under ultrasound irradiation, is reported. First, 1,4-diene 3 had been synthesized with Diels-Alder addition, and then the ketene addition reaction was carried out. Ultrasonic and non-ultrasonic conditions in the ketene addition reaction were investigated. Then, lactones (8 and 9) were obtained from ketene adducts. The structures of the molecules were illuminated by IR, and NMR spectroscopy techniques, especially Cosy spectroscopy. The test compounds improved antioxidant ability from 9.48% to 69.29% at concentration rates of 12.5-200 mg/L. The newly synthesized dichloro lactone 8 showed good antibacterial activity against gram-negative and –positive bacteria and also, antifungal activity. The antibiofilm activity of dichloro lactone 8 investigated and it showed 99.92 and 99.14% biofilm inhibiton activity againts Staphylococcus aureus and Pseudomonas aeruginosa, respectively at concentration of 250 mg/L. Moreover, it was displayed 100% Escherichia coli viability inhibition at concentrations of 125 and 250 mg/L.